Revert "scripts/travis/run-tests: use pip3"
Revert "scripts/travis/run-tests: use pip3"

This reverts commit b164f2e43106ba29af273ddf38ea6adaceb307ce.

thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext,thomastrapp/hext